Lobster prediction

LFAs 33/34 Moult & QualityMonitoring Project

~November 2011 Update~

Monitoring of lobster blood protein levels, shell hardness and moult stage was initiated in the summer 2004

with pre-season, during and post-season sampling. Over the course of the monitoring programme,

approximately 105,000 lobsters were sampled in 15 different sites in LFAs 33/34. The information collected

for this project is available on the Internet and allows people to look at lobster sex, size, blood protein, moult

stage and shell hardness by sampling location or dates.

Below is a breakdown of some of the pre-season sampling sites for 2011 compared to similar dates in 2010,

2009 and 2008.

Lobster Bay Jacquard’s Ridge Sambro

Sampling dateOct 272011

Oct 282010

Oct 282009

Oct 312008

Oct 282011

Oct 302010

Oct 272009

Nov 012008

Oct 242011

Oct 302010

Oct 272009

Nov 042008

Mean protein levels 8.8 10.3 8.5 10.0 8.8 9.0 9.3 9.8 8.8 10.4 10.2 9.5

% active pre-moult 1.6% 0% 0% 1.5% 1.6% 0% 3.2% 4.0% 0% 0% 0% 0.5%

% hard-shell 78.4% 80.0% 65.6% 70.9% 77.6% 93.6% 71.2% 77.5% 80.0% 92.0% 87.2% 85.0%

Yarmouth Inside Yarmouth Outside Port Latour Inside


Oct 262010

Oct 282009

Oct 302008

Oct 252011

Oct 252010

Oct 272009

Oct 282008

Oct 262011

Oct 272010

Oct 292009

Oct 142008


% active pre-moult 3.2% 4.3% 0% 0% 0% 0.8% 0% 0% 1.6% 1.6% 0% 0%

% hard-shell 68.8% 93.1% 80.0% 69.0% 76.0% 88.0% 72.0% 32.1% 78.4% 83.2% 95.2% 91.3%

Cape Sable Island Inside Cape Sable Island Outside St Mary’s Bay


Oct 262010

Oct 282009

Nov 012008

Oct 272011

Oct 252010

Oct 272009

Oct 312008

Oct 282011

Oct 292010

Oct 292009

Oct 242008


% active pre-moult 0.8% 0.8% 1.6% 0% 0.8% 0.8% 0.8% 0.5% 1.6% 2.4% 0% 0%

% hard-shell 91.2% 84.0% 96.8% 47.5% 92.0% 76.0% 98.4% 52.0% 80.0% 79.2% 69.6% 83.5%

Moose Harbour

Sampling date

Oct 272011

Oct 292010

Oct 302009

Nov 012008

Mean protein levels 7.9 8.1 8.3 7.9

% active pre-moult 0% 0% 0% 0%

% hard-shell 48.8% 58.4% 68.8% 73.0%

AVC Lobster Science Centre550 University Avenue - Charlottetown - PEI - Canada - C1A 4P3

Tel: (902) 894-2884 - Fax: (902) 894-2885 - [email protected] - www.LobsterScience.ca

What can we expect from the 2011 fall season?

Depending on the location, we have between 4-7 years of continuous data. We have looked at the

information collected so far and tried to see if we could predict with some level of certainty what will be

coming out of the water once the season opens at the end of November 2011. With an increasing number

of companies and individual fishermen using blood proteins as an indicator of quality, it is important to keep

in mind that several factors can influence blood protein levels such as moult cycle, water temperature,

health, diet, etc. and therefore, caution must be used when making predictions.

Overall, based on the 2011 pre-season sampling, lobsters landed at the start of the season inSouthwest Nova Scotia should be of similar condition, or slightly worse to those landed at the startof last year’s season. Based on blood protein levels, lobsters caught around the Port Latour Insidecould be more advanced in their recovery from the moult while lobsters from Cape Sable Inside &Outside areas have the lowest blood protein levels of all 10 sites sampled. However, Cape Sable

Inside & Outside also show the highest proportion of hard shelled lobsters from all sample sites.When looking at the combination of blood protein, moult stage and shell hardness together from thispre-season sampling, it is possible that lobsters landed from Yarmouth Inside, Yarmouth Outside andLobster Bay areas could be somewhat of lesser quality than last year. As advised in the past, extra

caution should be taken when deciding what product can be stored for later sale.

BLOOD PROTEIN LEVELS - BRIX INDEX - When looking at the 2011 pre-season sampling conducted in

those 10 sites, we see that only two sites have blood protein levels significantly below 8 on the Brix index:

Cape Sable Island both inside and outside. Overall, we also notice that sampled lobsters from only one site,

Port Latour Inside, have an average blood protein level that is higher than what was observed the last two

years. On the other hand, it appears that lobsters from Lobster Bay and Sambro areas have seen a significant

decrease in their average blood protein levels compared to last year’s pre-season sampling. Therefore,

based on blood protein levels alone, it appears that the 2011 pre-season sampling points toward a similar or

slower recovery from the moult, with perhaps better conditions in Port Latour Inside.

SHELL HARDNESS & MOULT CYCLE - Overall, very few lobsters assessed were in active pre-moult. This is

suggesting that the majority of lobsters have already moulted, while only an insignificant number will be

moulting in the weeks or days prior to the opening of the fall season. When looking at shell hardness, only

Cape Sable Island Inside and Outside had over 80% of the sampled lobsters classified as ‘hard shell,’ while

the Moose Harbour sample had less than 50% of the lobsters in hard shell. Overall, 7 out of the 10 sites had

a lower proportion of lobsters classified as hard shell compared to last year. Therefore, based on the shell

hardness alone, the 2011 pre-season sampling indicates that the proportion of softer lobsters at the start of

the fall season could be more significant than in the previous years.

Note: Only the latest sampling dates are shown here. The overall pattern throughout the year for the

parameters monitored was considered when predicting the quality of the LFAs 33/34 2011 fall season.

Confidence is highest for those locations where sampling was done closest to the start of the season.

WWW.LOBSTERSCIENCE.CA/MOULT

Lobster prediction

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